There are a variety of central vacuum generators in the marketplace which are used to generate a vacuum to which a hose can be attached and which then acts to create a suction in the hose so that debris in the form of dust, dirt and the like can be suctioned into the hose and thence into the generator where it is deposited and remains. After a certain period when the cannister operable connected to the central vacuum generator is full, the cannister is removed and the accumulated debris is dumped from the cannister. A typical one of such canisters and central vacuum generators is one made by Hayden.
The Hayden device uses a centrally positioned cone within the cannister and located below a cartridge filter. The vacuum is created by a motor driving a two(2) or three(3) stage utility impeller. The debris entering the cannister though the inlet to the cannister from the attached hose is intended to spin about the inside of the cone from the upper to the lower portion which is open because the cone is truncated. The debris is then deposited in the central portion of the cannister cone directly below the cone opening.
The problem with such canisters is that the technique for creating low and high pressure zones within the canister is not well understood with the result that efforts made to enhance the vacuum and deposit the debris properly in the cannister are unsatisfactory. The known techniques result in inefficient vacuuming action. Specifically, little of the debris deposited within the canister takes full advantage of the vortex rings created by the configuration of the Haydon apparatus.